<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
  
     div{
         width: 200px;
         height: 200px;
         background-color: blueviolet;
         /* 过度的属性 */
         /* transition-property:width; */
         /* 过度的时间 */
         /* transition-duration:1s; */
         /* 过度的动画 */
         /* transition-timing-function: linear; */
         /* 过度的延迟时间 */
         /* transition-delay: 2s; */
         transition: width,height: ; 1s linear 2s;

     }

     div:hover{
       width: 500px;
       height: 200px;
     }

    </style>
</head>
<body>


      <div></div>
    
</body>
</html>